The invention relates to a soldering device comprising:
a chamber; PA1 heating means for heating the objects for soldering present in the chamber; PA1 a transporting device present in the chamber for transporting the objects for soldering; PA1 a cleaning device for cleaning the gases present in the chamber, which cleaning device is connected to the chamber with a feed line and a discharge line; and PA1 a fan arranged in one of the lines.
Such a soldering device is known from U.S. Pat. No. 4,951,401.
The filter used in this known soldering device serves to remove waste products from the gases present in the soldering chamber. These waste products occur as a consequence of the soldering process taking place in the soldering chamber, for instance as a result of the reflow-soldering process, wherein the solder paste comprises substances which evaporate on heating. Waste products can further occur for instance due to evaporation of the fluxes used during the normal soldering using a solder wave.
These waste products are present in the soldering chamber mainly in gaseous form. When these gases are passed through the filter they will scarcely be restrained by the filter, so that the greater part of these waste products is fed back again to the soldering chamber and the filter has hardly any effect.
The object of the present invention is to provide such a soldering device wherein the filter is effective.
This object is achieved in that a cooling device is arranged in one of the lines.
As a result of this step the gases flowing through the filter have a lower temperature so that condensation of the harmful substances can occur and these remain behind in the filter. The effectiveness of the filter is thus increased.
According to a preferred embodiment the cooling device is combined with the cleaning device into one unit.
It will be apparent that, when cooling and cleaning take place inside the same unit, the effectiveness of the cleaning is greatest; precisely at the position where they are removed the harmful substances are cooled in order to cause condensation. Condensation therefore occurs at the location where the separation of the liquid substances takes place most effectively.
According to a second preferred embodiment the unit is adapted for stepwise alternating cooling of the gas and cleaning thereof by means of filters. This step also results in an improved effectiveness of the cleaning process.